sched/deadline: Fix warning in migrate_enable for boosted tasks
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 4.15
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
In the Linux kernel, the following vulnerability has been resolved: sched/deadline: Fix warning in migrate_enable for boosted tasks When running the following command: while true; do stress-ng --cyclic 30 --timeout 30s --minimize --quiet done a warning is eventually triggered: WARNING: CPU: 43 PID: 2848 at kernel/sched/deadline.c:794 setup_new_dl_entity+0x13e/0x180 ... Call Trace: <TASK> ? show_trace_log_lvl+0x1c4/0x2df ? enqueue_dl_entity+0x631/0x6e0 ? setup_new_dl_entity+0x13e/0x180 ? __warn+0x7e/0xd0 ? report_bug+0x11a/0x1a0 ? handle_bug+0x3c/0x70 ? exc_invalid_op+0x14/0x70 ? asm_exc_invalid_op+0x16/0x20 enqueue_dl_entity+0x631/0x6e0 enqueue_task_dl+0x7d/0x120 __do_set_cpus_allowed+0xe3/0x280 __set_cpus_allowed_ptr_locked+0x140/0x1d0 __set_cpus_allowed_ptr+0x54/0xa0 migrate_enable+0x7e/0x150 rt_spin_unlock+0x1c/0x90 group_send_sig_info+0xf7/0x1a0 ? kill_pid_info+0x1f/0x1d0 kill_pid_info+0x78/0x1d0 kill_proc_info+0x5b/0x110 __x64_sys_kill+0x93/0xc0 do_syscall_64+0x5c/0xf0 entry_SYSCALL_64_after_hwframe+0x6e/0x76 RIP: 0033:0x7f0dab31f92b This warning occurs because set_cpus_allowed dequeues and enqueues tasks with the ENQUEUE_RESTORE flag set. If the task is boosted, the warning is triggered. A boosted task already had its parameters set by rt_mutex_setprio, and a new call to setup_new_dl_entity is unnecessary, hence the WARN_ON call. Check if we are requeueing a boosted task and avoid calling setup_new_dl_entity if that's the case.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From 4.14.70 · fixed in 4.15
- Linux Linux
4.15